Process for preparing phosphonothioic chlorides and phosphinothioic chlorides and newproducts produced by said process



United States Patent Ofiicc 2,993,929 Patented July 25, 1961 PROCESS FORPREPARING PHOSPHONOTHIOIC CHLORIDES AND PHOSPHINOTHIOIC CHLO- RIDES ANDNEW PRODUCTS PRODUCED BY SAID PROCESS Kenneth H. Rattenbury, SouthChicago Heights, 111., aslsigner to Victor Chemical Works, a corporationof IllHOlS No Drawing. Filed May 14, 1957, Ser. No. 658,972

12 Claims. (Cl. 260543) This invention relates to a new process for theproduction of phosphonothioic dichlorides and phosphinothioic chlorides,and to new compounds produced by this process.

In particular, this invention relates to a process whereby compounds ofthe formula wherein R is alkyl, aryl, haloalkyl, haloaryl and A is thesame or different R, or a chlorine substituent, are prepared by reactingthe corresponding oxygen analog with phosphorus sulfides. There is thusprovided a simple process whereby phosphonic dichlorides and phosphinicchlorides are converted into the corresponding phosphonothioicdichlorides and phosphinothioic chlorides.

The products produced by this new process are valuable chemicalintermediates and may be used in the manufacture of many usefulcompounds. For example, the products produced by our invention may beused to form compounds having active insecticidal properties. Thus,phenylphosphonothioic dichloride may be used to manufacture EPN(O-ethyl, O-paranitrophenyl thionophenylphosphonate), a well knowninsecticide, according to the process shown in Us. Patent No. 2,503,390.Likewise, chloromethylphosphonothioic dichloride may be used to make'O-ethyl, O-paranitrophenyl thionochloromet-hylphosphonate by a similarprocess. This latter compound has been found to be a good insecticideagainst a wide variety of insects when used at concentrations of from0.005% to 0.02%.

My process is the only way that is presesntly known to makechloromethylphosphonothioic chlorides, which represent a class of newand useful chemical compounds. These new compounds may be represented bythe general formula wherein n may be from 1 to 3 and m is 1 or 2.Representative compounds are mono, di or trichloromethylphosphonothioicdichloride and his (mono, di or trichloromethyl) phosphinothioicchloride.

Generally, my invention contemplates a process which comprises simplymixing the phosphonic dichloride or phosphinic chloride with phosphorussulfide reactants having an oxygen-replaceable sulfur substituent linkedto a phosphorus substituent by means of a double'bond in accordance withthe following illustrative reactions:

wherein R is a member of the class consisting of alkyl, aryl, haloalkyland haloaryl, and A is the same or a different R or a chlorinesubstituent. The reactants are then simply heated until the reaction iscomplete. Normally the reaction is'conducted at reflux temperature whena phosphorus sulfide such as P 5 is used; this temperature will Varydepending upon the particular reactants used but is generally in therange of to 250 C. When PSCI is used, it is necessary to conduct thereaction under pressure due to the low boiling point of PSCl It isimportant that the temperature for this latter reaction be in the rangeof 180 to 230 C. The pressure is not important per se but is used tofacilitate the reaction so that temperatures above the boiling point ofthe reacants may be used. Generally, pressures of 250-400 p.s.i. aresatisfactory.

The time required for the reaction is not critical but should be ofsufiicient duration to substantially complete the reaction. Since thereaction involves the exchange of oxygen and sulfur, the length of thereaction time is of importance with regard to the completeness of thereaction. Thus, some of the following examples show an initial reactionperiod, after which the purity is checked, followed by a furtherreaction period. This. double reaction period is not necessary to theprocess but serves only as a means of checking the progress of thereaction. Likewise, some examples show washing the product .with icewater, etc. These techniques are not necessary to the new process butserve to produce a purer product for purposes of identification andanalysis.

The phosphorus sulfide reactants include sulfides such as P285, P483,P487, and however, the use Of P285 is generally preferred.

The reactants in all cases may be commercial grade products as extremepurity is not necessary to carry out the reaction. In the case of P S.and PSCl these products are standard articles of commerce.Phenylphosphonic dichloride and chloromethylphosphonic dichloride mayalso be obtained commercially.

The following examples illustrate the process of the present invention.

Example I 2508.0 gms. of ClCI-I POCl (15.0 moles)and 666.0 gms'. of P 5(3.0 moles) were placed in a distilling flask equipped with a refluxcondenser. The mixture was then heated at a reflux temperature of to180C. for three hours. It was weighed and found to have lost 33.0 gms.The flask was then evacuated to an absolute pressure of 10 mm. ofmercury and heated to a liquid temperature of 160 C., at which thevapor'temperature'was 88 C. The resulting distillate weighed 2049.4 gms.and was redistilled at a pressure of 30 mm. 'of mercury. Thechloromethylphosphonothioic dichloride was collected over a vaportemperature range of 88-89 C.

It weighed 1589.3 gms. and analyzed asfollows: n

Percent P Percent Cl Percent 8 Analysis 17.3 58. 0 17. 1 Theory 16.9 58.0 l7. 4

bean aphid. It was found to bean effective insecticide in all cases atconcentrations of 0.005% to 0.5% in acetone spray solution.

Example II 83.8 gms. (0.5 mole) of ClCH POCl and 169.5 gms. (0.5 moleplus 100% excess) of PSCl were placed in a one liter glass liner. Theliner was then placed in a small autoclave and placed under 300 psi.nitrogen pressure. It was heated at 220 C.i10 for 5 /2 hours. It wasthen cooled, placed in a distilling flask and the excess P801 and P001removed at atmospheric pressure. The remaining product was cooled to 15C., stirred with 18 cc. of water, separated, and dried. It was thenplaced in a distilling flask, evacuated to an absolute pressure of 30mm. of mercury and distilled. The chloromethylphosphonothioic dichloridefraction distilling at a vapor temperature from 90 to 92 C. wascollected and analyzed as follows: n =1.5742.

Percent P Percent 01 Percent S Theory Analysis Example III Using thesame equipment as in Example H, 44.2 gms. of C H POCl (0.3 mole) and101.8 gms. of PSCl (0.3 mole plus 100% excess) were charged to theautoclave and placed under 300 p.s.i. nitrogen pressure. The charge washeated at 200 to 215 C. for six hours. The charge was cooled and theexcess PSCl and POC1 removed by distilling at atmospheric pressure. Theremaining product was cooled to 10 C. and washed twice with ice water.The resulting organic layer was dried over calcium chloride anddistilled through a Vigreux column at a pressure of 50 mm. of mercury.The fraction distilling at a vapor temperature of 93 C. was collectedand analyzed as follows: n ==1.5399.

Percent P Percent Cl Percent S Theory Analysis This product wasethylphosphonothioic dichloride.

Example IV Using the same equipment as in Example II, 87.7 gms. (0.45mole) of C H POCl and 152.5 gms. of PSCl (0.45 mole plus 100% excess)were placed under a pressure of 300 p.s.i. and heated at 235 to 255 C.for 5 hours. After removing the excess PSCl and POCl at atmosphericpressure, the crude product was washed twice with ice water and thendried over calcium chloride. It was distilled using a Vigreux column.The phenylphosphonothioic dichloride was collected at a vaportemperature of 64 C. at a pressure of 1 mm. of mercury and analyzed asfollows: n =l.6228.

Percent P Percent 01 Percent S Theory Analysis Example V 200 C. forthree hours.

4 Vigreux column collecting the fraction distilling at a vaportemperature of 101 to 105 C. at 1 mm. of mercury. This parachlorophenylphosphonothioic dichloride analyzed as follows: n =1.6323.

236.5 gms. of Cl CPOCl (1.0 mole) and 44.4 gms. of P S (0.2 mole) wereplaced in a 500 cc. distilling flask equipped with a reflux condenserand heated to a reflux temperature of 206-210 C. The heating wascontinued for eight hours, at which time a sample indicated that thereaction was incomplete. Therefore an additional 11.1 gms. of P S wereadded and the mixture refluxed for an additional 20 hours. The productwas distilled at 195 to 200 C. under slightly reduced pressure. Theproduct, weighing 139.5 gms., was an orange solid,trichloromethylphosphonothioic dichloride, and analyzed as follows:

Percent P Percent 01 Percent S Theory 12. 3 70. 3 12. 7 Analysis l2. 469. 9 12. 2

Example VII 118.2 gms. of (C H POCl (0.5 mole) and 22.2 gms. of P 8 (0.1mole) were placed in a 300 cc. distilling flask equipped with a refluxcondenser and heated at 190 to The product was distilled at 170 to 175C. at a pressure of 3-4 mm. of mercury and the distillate redistilledcollecting the fraction distilling at a vapor temperature of 134 to 139C. at a pressure of 1 mm. of mercury. Since analysis showed the reactionWas not complete, 2.0 grns. of P S were added and the mixture was heatedat 190 to 200 C. for two hours. The product was then distilled at to C.at 2 mm. of mercury to yield 69.6 gms. of diphenylphosphinothioicchloride [(C H PSC1], which had an index of refraction n =1.6586.

As a further check on purity the product was stirred with 100 cc. ofdistilled Water at 30 C. for one hour, dried, and rcdistilled to give aproduct with an index of refraction n =l.6587. This product analyzed:

and 13.3 gms. of P S were placed in a 100 cc. distilling flask and thenheated at to C. for two hours. The flask was then evacuated and theproduct distilled collecting the fraction distilling at a vaportemperature of 107 C. at 1 mm. of mercury. The product was furtherpurified by washing with water and then redistilled. The resulting ethylphcnylphosphinothioic chloride analyzed: n =1.6035.

Percent P Percent Cl Percent S Theory 15.2 17. 4 15.7 Analysis .1 15. 717. 0 1.1. 3

Example 1X 45.4 gms. of (CICHQ POCI (0.25 mole) were heated with 11.1gms. P 8 at 160 to 180 C. for three hours. The charge was then cooledand evacuated to a pressure of 1 mm. of mercury. After removal ofvolatiles, the product was washed with ice water, dried and distilled ata vapor temperature of 80 to 85 C. at 3 mm. of mercury. The product, bis(chloromethyl) phosphinothioic chloride, weighed 15.4 gms. and analyzedas follows:

Percent P Percent 01 Percent S Theory 15. 7 63. 9 16. 2 Analysis 15. 963. 0 16. 7

The phrase phosphorus sulfide reactant in the claims is not intended tobe restricted to binary compounds but includes compounds such asphosphorus thiohalides (e.g., PSCl The foregoing detailed descriptionhas been given for clearness of understanding only, and no unnecessarylimitations should be understood therefrom, as modifications will beobvious to those skilled in the art.

I claim: 1. A process for preparing a compound of the formula A s I]P-Gi 4. The process of claim 1 wherein the phosphorus sulfide reactantis P 8 5. The process of claim 1 wherein the phosphorus sulfide reactantis PSCl 6. A process for preparing a product of the formula S (01 0Hit-n) ml (01) 3-m wherein n is a positive integer of 1-3 and m is apositive integer of at least 1 and not more than 2, which oomprises:reacting at temperatures of about l255 C. a compound of the formula witha phosphorus sulfide reactant selected from the group consisting of P 8P 8 P 8 and P301 7. The process of claim 6 wherein the phosphorussulfide reactant is P 5 8. The process of claim 6 wherein the phosphorussulfide reactant is P 8 9. The process of claim 6 wherein the phosphorussulfide reactant is P 8 10. The process of claim 6 wherein thephosphorus sulfide reactant is PSC13.

11. A compound of the formula s l (C1aC)mEC1a-m wherein m is a positiveinteger of at least 1 and not more than 2.

12. A compound of the formula S 01 ll ClsC-P References Cited in thefile of this patent UNITED STATES PATENTS Kuh Mar. 16, 1954 Craig et a1Nov. 22, 1955 OTHER REFERENCES Walsh et al.: J.A.C.S., vol. 77, page 931(1955).

UNITED STATES PATENT oEFIcE CERTIFICATE OF CGRECTION Patent No, 2993,929I July 25, 1961' Kenneth H. Rattenbury "corrected below,

Column 5 lines 38 to 41 the formula should appear as shown below insteadof as in the patent:

P-Cl R Signed and sealed this 9th day of January 19620 (SEAL) Attest:

ERNEST W. WIEE DAVID L. LADD Attesting Officer Commissioner of Patents

1. A PROCESS FOR PREPARING A COMPOUND OF THE FORMULA
 11. A COMPOUND OFTHE FORNULA